step(ci,(ci,s),tm(s,[pri(naught,[]),pri(naught,[])],pri(lst,[pri(pc,[ctxm(beta_2_ci_,dot,s,i_s,c_s),ctxm(beta_2_ci_,u,bsn,i_bsn,i_bsn),ctxm(beta_2_ci_,r,dom, (dom,r,beta_2_), (dom,r,beta_2_))]),ctxm(beta_2_ci_,r,dom, (dom,r,beta_2_), (dom,r,beta_2_))]))).